Breast Edema after Conservative Surgery for Early-Stage Breast Cancer: A Retrospective Single-Center Assessment of Risk Factors.

Breast-conserving surgery (BCS) is the standard of care for early-stage breast cancer. We retrospectively enrolled 530 patients (mean age: 62.96 ± 12.69 years) undergoing BCS between January 1, 2018, and December 31, 2019. During the COVID-19 pandemic, all patients with at least 1 year of follow-up were telephonically asked after surgery to provide clinical signs and symptoms attributable to postoperative breast cancer-related lymphedema of the breast (BCRL-B). Thirty-one (5.8%) patients reported breast edema and were visited to measure the tissue dielectric constant (TDC) and to assess the induration of the skin. There was a difference seen in treatment with lumpectomy + ALND performed more frequently in patients with (29%) than without (12%) BCRL-B. In the subgroup of patients with BCRL-B (n=31), significantly higher values of local total water were calculated in the nine patients who underwent Lump + ALND procedure (1.86 ± 0.48 vs. 1.48 ± 0.38; p = 0.046). Among patients with BCRL-B (n=31), in eight patients (25.8%) tissue induration measured with SkinFibroMeter was >0.100 N, thus suggesting tissue fibrosis. Cumulative survival probability at 1-year after surgery was 0.992. No statistical differences in 1-year survival after surgery were found for type of surgery (p = 0.890) or absence/presence of BCRL-B (p = 0.480). In univariate logistic regression, only lumpectomy + ALND surgery (p = 0.009) and any subsequent axillary lymph node removal surgery (p = 0.003) were associated with BCRL-B. Both of these variables were also found to be statistically significant in the multivariate regression model. Further prospective research is warranted to analyze potentential predictors of BCRL-B and to reduce/ prevent this complication.

Fungal Planet description sheets: 1383-1435.

Novel species of fungi described in this study include those from various countries as follows: Australia, Agaricus albofoetidus, Agaricus aureoelephanti and Agaricus parviumbrus on soil, Fusarium ramsdenii from stem cankers of Araucaria cunninghamii, Keissleriella sporoboli from stem of Sporobolus natalensis, Leptosphaerulina queenslandica and Pestalotiopsis chiaroscuro from leaves of Sporobolus natalensis, Serendipita petricolae as endophyte from roots of Eriochilus petricola, Stagonospora tauntonensis from stem of Sporobolus natalensis, Teratosphaeria carnegiei from leaves of Eucalyptus grandis × E. camaldulensis and Wongia ficherai from roots of Eragrostis curvula. Canada, Lulworthia fundyensis from intertidal wood and Newbrunswickomyces abietophilus (incl. Newbrunswickomyces gen. nov.) on buds of Abies balsamea. Czech Republic, Geosmithia funiculosa from a bark beetle gallery on Ulmus minor and Neoherpotrichiella juglandicola (incl. Neoherpotrichiella gen. nov.) from wood of Juglans regia. France, Aspergillus rouenensis and Neoacrodontium gallica (incl. Neoacrodontium gen. nov.) from bore dust of Xestobium rufovillosum feeding on Quercus wood, Endoradiciella communis (incl. Endoradiciella gen. nov.) endophytic in roots of Microthlaspi perfoliatum and Entoloma simulans on soil. India, Amanita konajensis on soil and Keithomyces indicus from soil. Israel, Microascus rothbergiorum from Stylophora pistillata. Italy, Calonarius ligusticus on soil. Netherlands, Appendopyricularia juncicola (incl. Appendopyricularia gen. nov.), Eriospora juncicola and Tetraploa juncicola on dead culms of Juncus effusus, Gonatophragmium physciae on Physcia caesia and Paracosmospora physciae (incl. Paracosmospora gen. nov.) on Physcia tenella, Myrmecridium phragmitigenum on dead culm of Phragmites australis, Neochalara lolae on stems of Pteridium aquilinum, Niesslia nieuwwulvenica on dead culm of undetermined Poaceae, Nothodevriesia narthecii (incl. Nothodevriesia gen. nov.) on dead leaves of Narthecium ossifragum and Parastenospora pini (incl. Parastenospora gen. nov.) on dead twigs of Pinus sylvestris. Norway, Verticillium bjoernoeyanum from sand grains attached to a piece of driftwood on a sandy beach. Portugal, Collybiopsis cimrmanii on the base of living Quercus ilex and amongst dead leaves of Laurus and herbs. South Africa, Paraproliferophorum hyphaenes (incl. Paraproliferophorum gen. nov.) on living leaves of Hyphaene sp. and Saccothecium widdringtoniae on twigs of Widdringtonia wallichii. Spain, Cortinarius dryosalor on soil, Cyphellophora endoradicis endophytic in roots of Microthlaspi perfoliatum, Geoglossum lauri-silvae on soil, Leptographium gemmatum from fluvial sediments, Physalacria auricularioides from a dead twig of Castanea sativa, Terfezia bertae and Tuber davidlopezii in soil. Sweden, Alpova larskersii, Inocybe alpestris and Inocybe boreogodeyi on soil. Thailand, Russula banwatchanensis, Russula purpureoviridis and Russula lilacina on soil. Ukraine, Nectriella adonidis on overwintered stems of Adonis vernalis. USA, Microcyclus jacquiniae from living leaves of Jacquinia keyensis and Penicillium neoherquei from a minute mushroom sporocarp. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Boers J, Holdom D, et al. 2022. Fungal Planet description sheets: 1383-1435. Persoonia 48: 261-371. https://doi.org/10.3767/persoonia.2022.48.08.

Congenital chylothorax: Current evidence-based prenatal and post-natal diagnosis and management.

Congenital chylothorax is an uncommon condition but represents the main cause of congenital pleural effusion during the neonatal period. It usually appears before birth, both as an isolated disorder or in association with hydrops fetalis, negatively affecting the subsequent neonatal outcome. Prenatal treatment is usually considered to ensure a satisfactory lung development in case of moderate to severe pleural effusion or in the presence of hydrops, although consensus on treatment timing and modalities has not been reached to date. Both medical and surgical therapeutic strategies are available to treat this condition and novel treatment options have been recently attempted with acceptable results in both prenatal and post-natal setting. The heterogeneous clinical presentation of congenital chylothorax together with its rarity, its numerous etiologies and the absence of a highly effective treatment renders the diagnostic and therapeutic approach difficult to standardize. In addition, adequate visualization of the lymphatic system is complex, especially in small neonates, although new promising techniques have been developed lately and may contribute to improved management of this serious but infrequent condition. This review focuses on the current evidence base for the diagnosis and treatment options for congenital chylothorax, suggesting a rational diagnostic and therapeutic approach both in the prenatal and in the neonatal period.

Surgical treatment of cyst of the canal of Nuck and prevention of lymphatic complications: A single-center experience.

The canal of Nuck is a residue of the peritoneal evagination that runs along the round ligament through the inguinal canal in women. Its partial or total patency can lead to a cystic lymphangioma (CL). CL of the canal of Nuck in an adult female is a rare entity and its clinical diagnosis can be difficult or incorrect. Ultrasonography can be useful to identify the nature of groin masses. A potential CL of the canal of Nuck should always be considered in the differential diagnosis of inguinal swelling in adult females. Even if it is possible to consider conservative treatment, the optimal therapeutic option is surgical excision of the cystic mass and closure of the inguinal ring by an anterior approach. In this study, we report a case series of four women affected by a cyst of the canal of Nuck to underline the surgical treatment's therapeutic role of this pathological condition and the importance of preliminary identification of lymphatic vessels with BPV (Blue Patent Violet) in order to prevent lymphatic injuries such as lymphorrea and lymphocele in the groin after surgery due to the disruption of inguinal lymph nodes and lymphatics.

Early fetal hydropic changes are associated with moderate dilatation of the brain ventricular system: A clue to a possible link between cervical lymphatic engorgement and ventricular dilatation?

The aim of this study is to assess whether early cervical lymphatic obstruction is associated with a sonographically detectable dilatation of the ventricular system in the 1st trimester of pregnancy. In particular, the objective is to assess whether fetuses with non-immune hydrops fetalis (NIHF), cystic hygroma, or enlarged nuchal translucency (NT) have a greater atrial width/biparietal diameter (AW/BPD) ratio than normal at time of the combined first trimester screening scan. This retrospective study included 96 first trimester fetuses (33 normal and 63 with various degree of cervical lymphatic engorgement). Inclusion criteria were CRL in the 45-84 mm range and availability of one or more three-dimensional volume datasets of the fetal head, acquired from the BPD plane. Each three-dimensional volume dataset was opened and multiplanar correlation employed to align the three orthogonal planes. The ratio between the atrial width and the BPD (AW/BPD ratio) was used to evaluate the possible presence of increased amount of cerebrospinal fluid. Abnormal cases were placed into 4 categories: 1) enlarged non-septated NT 2.5-3.9 mm, no hydrops; 2) grossly enlarged non-septated NT / edema >3.9 mm; 3) cystic hygroma and/ or NIHF; 4) major anomalies with NT <2.5 mm. Presence of dilatation of the laterocervical jugular lymphatic sacs, karyotype and presence of congenital anomalies were also recorded. The One-way ANOVA test was used to compare means. Intra- and inter-observer variability were also assessed. The AW/BPD ratio was found to be significantly higher in fetuses with grossly enlarged NT/nuchal edema and NIHF/septated cystic hygroma than in normal (p <0.05 and p <0.01, respectively). Also, the AW/BPD ratio was significantly higher in NIHF/septated cystic hygroma than in enlarged NT 2.5-3.9 mm (p <0.05). In case of enlarged NT (2.5-3.9 mm), the AW/BPD ratio is significantly higher in presence of JLS (p <0.01). At the end of the first trimester, presence of cervical lymphatic engorgement, in terms of grossly enlarged NT, nuchal edema, septated cystic hygroma, and NIHF, is statistically associated with a moderate dilatation of the ventricular system. Of note, among fetuses with moderately enlarged NT, those with evidence of dilatation of the JLS show a statistically significant increase in the AW/BPD ratio.

Conservative management of chylous ascites after oncological surgery for peripheral neuroblastic tumors in pediatric patients.

Chylous ascites may complicate the postoperative course of abdominal surgery mainly due to the iatrogenic disruption of the lymphatic channels during extensive retroperitoneal dissection. Sparse data are available regarding treatment; however, in many cases a recommended first-line treatment approach is by way of enteral feeding, consisting of a formula high in medium-chain triglycerides (MCTs) together with a complete total parenteral nutrition teamed with somatostatin (or an equivalent). Nonetheless, the ligation of chylous fistulae, together with the application of Fibrin glue, as well as the creation of peritoneal-venous shunts have also been documented. The aims of this study are to document incidence of postoperative chylous ascites following resection of abdominal peripheral neuroblastic tumors, evaluate efficacy of the management of chylous ascites, and investigate the main risk factors. A survey was carried out over a span of six years, from March 2010 to March 2016 at Giannina Gaslini Children's Hospital involving seventy-seven children with resections of peripheral neuroblastic tumors. Incidence rate of postoperative chylous ascites following a normal diet was 9% (n=7). Treatment using total parenteral nutrition with octreotide resulted in a complete recovery from chylous ascites within a 20 day period without recurrence. Length of operative time, nephrectomy, and the extension of lymphadenectomy were all significantly associated with a higher incidence of postoperative chylous ascites (p<0.05) which also lengthened hospital stay (p<0.05) and possibly delayed beginning adjuvant chemotherapy.

Procedural Recommendations for Lymphoscintigraphy in the Diagnosis of Peripheral Lymphedema: the Genoa Protocol.

INTRODUCTION: Lymphoscintigraphy is the gold standard for imaging in the diagnosis of peripheral lymphedema. However, there are no clear guidelines to standardize usage across centers, and as such, large variability exists. The aim of this perspectives paper is to draw upon the knowledge and extensive experience of lymphoscintigraphy here in Genoa, Italy, from our center of excellence in the assessment and treatment of lymphatic disorders for over 30 years to provide general guidelines for nuclear medicine specialists. METHOD: The authors describe the technical characteristics of lymphoscintigraphy in patients with limb swelling. Radioactive tracers, dosage, administration sites, and the rationale for a two-compartment protocol with the inclusion of subfascial lymphatic vessels are all given in detail. RESULTS: Examples of lymphoscintigraphic investigations with various subgroups of patients are discussed. The concept of a transport index (TI) for semi-quantitative analysis of normal/pathological lymphatic flow is introduced. Different concepts of injection techniques are outlined. DISCUSSION: It is past time that lymphoscintigraphy in the diagnosis of lymphatic disorders becomes standardized. This represents our first attempt to outline a clear protocol and delineate the relevant points for lymphoscintigraphy in this patient population.

Decreasing and preventing lymphatic-injury-related complications in patients undergoing venous surgery: A new diagnostic and therapeutic protocol.

Lymphatic complications following great and small saphenous vein surgery show a varying and non-negligible incidence in the literature. We undertook this study to investigate a new protocol to reduce lymphatic injuries in patients undergoing venous surgery. Eighty-six patients with lower limb venous insufficiency and varices were treated. Lymphoscintigraphy was performed preoperatively in 65 of them and postoperatively in 19. Blue dye was used in all patients and blue lymph nodes and lymphatics were identified intra-operatively and preserved or used to perform multiple lymphatic-venous anastomoses (MLVA). Patients were followed up fora period varying from 3 months to 6 years. Sixty-six patients were treated by greater saphenectomy and varicectomy, 12 patients had crossectomy and varicectomy, 4 patients underwent greater saphenectomy and varicectomy associated with MLVA, and 4 patients were treated by small saphenous vein stripping and varicectomy. No lymphatic complications occurred in any of the patients. A decrease of over 75% of excess volume was observed in 4 patients treated by MLVA. Lymphoscintigraphy showed normalization in the Transport Index in 4 patients treated with MLVA. Our results demonstrate that accurate diagnostic investigation and proper surgical technique is of paramount importance in the effort to avoid lymphatic complications during venous surgery.

Brain lymphatic drainage system in fetus and newborn: Birth of a new era of exploration.

A peculiar brain lymphatic drainage system has been recently fully recognized in animals and humans. It comprises different draining pathways, including the lymphatic system, the perivascular drainage pathway, and the cerebrospinal fluid (CSF) drainage routes. Although scant data are available about its function during the neonatal period, it may play a role in neonatal brain diseases. In this review, we focus on the actual knowledge of brain lymphatic drainage system, and we hypothesize potential implications of its impairment and dysfunction in major neonatal neurological diseases.

FSH suppression and tumour control in patients with prostate cancer during androgen deprivation with a GnRH agonist or antagonist.

BACKGROUND: Gonadotropin releasing hormone (GnRH) antagonists suppress follicle-stimulating hormone (FSH) to lower levels than GnRH agonists. This may partially explain the differences between these agents on prostate cancer outcomes. In this post-hoc analysis, FSH and prostate specific antigen (PSA) responses and the impact of cross-over from leuprolide to degarelix were evaluated from a 1-year comparative study (CS21) and its extension study (CS21A). MATERIALS AND METHODS: Overall, 610 patients were enrolled in CS21, wherein PSA and FSH levels were evaluated monthly. CS21A evaluated 386 patients, including those previously treated with degarelix (n = 251) who continued to receive degarelix, and those previously treated with leuprolide (n = 135) who crossed-over to receive degarelix. PSA and FSH levels were evaluated in CS21A for 3 months after cross-over. The associations between measurements were assessed using Spearman's correlation coefficient. The impact of class variables on FSH suppression were evaluated using Analysis of Variance. RESULTS: Rapid PSA and FSH suppression was observed and maintained in the degarelix arm (CS21 and CS21A), while patients on leuprolide experienced rising PSA during CS21. Patients crossed-over from leuprolide to degarelix achieved a suppression of FSH and a significant PSA decrease. PSA and FSH levels were significantly (p < .05) correlated at months 1, 3, 6, 12 and 13 in the degarelix arm. CONCLUSIONS: Significant FSH suppression with GnRH antagonists may explain its advantage over GnRH agonists in terms of better prostate cancer control. The effect of profound FSH suppression is analogous to the need for profound testosterone suppression for tumor control.

Targeting androgen-independent pathways: new chances for patients with prostate cancer?

Androgen deprivation therapy (ADT) is the mainstay treatment for advanced prostate cancer (PC). Most patients eventually progress to a condition known as castration-resistant prostate cancer (CRPC), characterized by lack of response to ADT. Although new androgen receptor signaling (ARS) inhibitors and chemotherapeutic agents have been introduced to overcome resistance to ADT, many patients progress because of primary or acquired resistance to these agents. This comprehensive review aims at exploring the mechanisms of resistance and progression of PC, with specific focus on alterations which lead to the activation of androgen receptor (AR)-independent pathways of survival. Our work integrates available clinical and preclinical data on agents which target these pathways, assessing their potential clinical implication in specific settings of patients. Given the rising interest of the scientific community in cancer immunotherapy strategies, further attention is dedicated to the role of immune evasion in PC.

The prognostic value of stromal and epithelial periostin expression in human breast cancer: correlation with clinical pathological features and mortality outcome.

BACKGROUND: PN is a secreted cell adhesion protein critical for carcinogenesis. In breast cancer, it is overexpressed compared to normal breast, and a few reports suggest that it has a potential role as a prognostic marker. METHODS: Tumour samples obtained at the time of mastectomy from 200 women followed for a median time of 18.7 years (range 0.5-29.5 years) were investigated through IHC with a polyclonal anti-PN antibody using tissue microarrays. Epithelial and stromal PN expression were scored independently according to the percentage of coloured cells; the 60th percentile of PN epithelial expression, corresponding to 1%, and the median value of PN stromal expression, corresponding to 90%, were used as arbitrary cut-offs. The relationships between epithelial and stromal PN expression and clinical-pathological features, tumour phenotype and the risk of mortality following surgery were analysed. Appropriate statistics, including the Fine and Gray competing risk proportional hazard regression model, were used. RESULTS: The expression of PN in tumour epithelial cells was significantly lower than that which was observed in stromal cells (p < 0.000). No specific association between epithelial or stromal PN expression and any of the clinical-pathological parameters analysed was found as it was observed in respect to mortality when these variables were analysed individually. However, when both variables were considered as a function of the other one, the expression of PN in the stromal cells maintained a statistically significant predictive value with respect to both all causes and cancer-specific mortality only in the presence of high epithelial expression levels. No significant differences in either all causes or BCa-specific mortality rates were shown according to epithelial expression for tumours displaying higher stromal PN expression rates. However, the trends were opposite for the higher stromal values and the patients with high epithelial expression levels denoted the group with the worst prognosis, while higher epithelial values in patients with lower stromal expression levels denoted the group with the best prognosis, suggesting that PN epithelial/stromal interactions play a crucial role in breast carcinogenesis, most likely due to functional cross-talk between the two compartments. On the basis of PN expression in both compartments, we defined 4 subgroups of patients with different mortality rates with the group of patients characterized by positive epithelial and low stromal PN expression cells showing the lowest mortality risk as opposed to the groups of patients identified by a high PN expression in both cell compartments or those identified by a low or absent PN expression in both cell compartments showing the worst mortality rates. The differences were highly statistically significant and were also retained after multiparametric analysis. Competing risk analysis demonstrated that PN expression patterns characterizing each of previous groups are specifically associated with cancer-specific mortality. CONCLUSIONS: Although they require further validation through larger studies, our findings suggest that the patterns of expression of PN in both compartments can allow for the development of IHC "signatures" that maintain a strong independent predictive value of both all causes and, namely, of cancer-specific mortality.

Chyloperitoneum: Diagnostic and Therapeutic Options.

Chyloperitoneum is not rare and is often associated with other chylous disorders particularly in more complex clinical conditions. An accurate diagnostic study is indispensable to plan the correct therapeutic approach, and we examined the long-term outcomes of our experience in the management of primary and secondary chyloperitoneum in fifty-eight patients (50 adults and 8 children; 34 primary and 24 secondary forms). Diagnostic assessment consisted of aracentesis, whole body lymphoscintigraphy, lymphangio-MR, and lymphangio-CT (LAG-CT). The management of chyloperitoneum consisted initially of non-operative procedures (MCT diet, TPN, octreotide). Surgical treatment was performed in patients not responsive to conservative methods and involved different options using surgical and microsurgical approaches. Microsurgical techniques included chylousvenous shunts connecting chyliferous vessels and mesenteric veins. Fibrin glue or platelet gel injection at the site of the chylous leakage was also used to treat one case of refractory secondary chyloperitoneum. Patients were followed clinically and instrumentally (echography and labs tests) for 6 months to over 5 years. We found that LAG-CT was the primary diagnostic modality to provide precise topographic information concerning the site, cause, and extension of chylous pathology, all of which allowed proper planning of therapeutic procedures. Thirty-four patients did not have a relapse of the chyloperitoneum and 22 patients had a persistence of a small quanitity of ascites with no protein imbalance. We observed early relapse of chylous ascites in 2 cases that required a peritoneal-jugular shunt leading to good outcomes. An accurate diagnostic study (above all LAG-CT) and a microsurgical approach proved to represent an effective management of chyloperitoneum refractory to non-operative treatment.

Congenital Chylothorax of the Newborn: Diagnosis and Treatment in Three Pictures.

There is general agreement regarding the evident need for an international, multicenter trial including long-term follow-up to establish the correct criteria for diagnosing and managing congenital chylothorax. In an attempt to identify these criteria, which could then be used to draft a prospective multicenter trial, we propose three flow-charts showing three algorithms that could be used to: 1) obtain a definitive diagnosis of pleural chylous effusion; 2) specifically focus on chyle leakage evolution and etiology of chylothorax; and 3) focus on the management of congenital chylothorax. The aim of the algorithms we propose is to build the basis on which a strongly needed multicenter trial might be structured.

LYMPHODYSPLASIA AND KRAS MUTATION: A CASE REPORT AND LITERATURE REVIEW.

Cardio-facio-cutaneous (CFC) syndrome is a very rare and sporadic disease whose characteristics include dysmorphic facial appearance, ectodermal abnormalities, cardiac abnormalities, growth retardation and neurodevelopmental delay. This syndrome is classified as one of the RAS syndromes which are caused by altered signal transduction of the RAS/MAPK (mitogen activated protein kinase) pathway due to the mutation of genes including BRAF, MEK1/2, HRAS and KRAS. Other RAS syndromes, such as Costello syndrome and Noonan syndrome, share clinical features with CFC. Moreover, patients with the same clinical phenotype may have different molecular diagnoses. Clinical diagnosis is the starting pointfor correct classification. We describe the clinical data of one case of CFC syndrome, genetically determined by KRAS mutation, that involved chylothorax, lymphedema, sinus pericranii, craniosynostosis, and seizures. This is the second case report of the literature.

INTERMITTENT NEGATIVE PRESSURE THERAPY IN THE COMBINED TREATMENT OF PERIPHERAL LYMPHEDEMA.

Intermittent negative pressure devices were initially developed by NASA to enhance blood perfusion and combat a reduction in orthostatic tolerance. Investigational studies have demonstrated that the pressure differential produces changes in the blood and cardiac systems and also documented changes in weight and cellulite in obese patients. Although the mechanisms are not known, previous investigation has also reported changes in lymphedematous limbs. These initial results suggested to us that the inclusion of intermittent negative pressure into a lymphedema treatment protocol would be beneficial. We subsequently undertook a study of 50 patients with lymphedema adding intermittent negative pressure to our CLyFT protocol and compared them to the CLyFT protocol without intermittent negative pressure. We found a significant difference between the groups with an additional 7% reduction in lymphedema volume (p = 0.008). Our study results indicate that the inclusion of intermittent negative pressure therapy into the CLyFT protocol was beneficial and further incorporation into other protocols should be investigated.

Lymphoscintigraphy patterns in newborns and children with congenital lymphatic dysplasia.

We performed lymphoscintigraphy on 31 patients (newborns and children) affected by congenital lymphatic dysplasia according to our previously published protocol. Congenital lymphatic dysplasia may present with various degrees of clinical severity, ranging from nonimmune hydrops fetalis with visceral effusions to lymphedema alone. We recommend that lymphoscintigraphy should be strongly considered in all patients with signs of lymphatic dysplasia, including those with minimal and initial signs of lymphatic impairment, in order to obtain a very early diagnosis and to start treatment. Lymphoscintigraphy is safe and useful in the diagnosis of lymphatic dysplasia in the newborn and children. Moreover, it is well tolerated by patients and well accepted by their parents.

Role of microRNAs in malignant mesothelioma.

Malignant mesothelioma (MM) is an aggressive tumor, mainly derived from the pleura, which is predominantly associated with exposure to asbestos fibers. The prognosis of MM patients is particularly severe, with a median survival of approximately 9-12 months and latency between exposure and diagnosis ranging from 20-50 years (median 30 years). Emerging evidence has demonstrated that tumor aggressiveness is associated with genome and gene expression abnormalities; therefore, several studies have recently focused on the role of microRNAs (miRNAs) in MM tumorigenesis. miRNAs are small non-protein coding single-stranded RNAs (17-22 nucleotides) involved in numerous cellular processes that negatively regulate gene expression by modulating the expression of downstream target genes. miRNAs are often deregulated in cancer; in particular, the differential miRNA expression profiles of MM cells compared to unaffected mesothelial cells have suggested potential roles of miRNAs as either oncogenes or tumor suppressor genes in MM oncogenesis. In this review, the mechanism of MM carcinogenesis was evaluated through the analysis of the published miRNA expression data. The roles of miRNAs as diagnostic biomarkers and prognostic factors for potential therapeutic strategies will be presented and discussed.